I asked Gleason Sensei almost this exact question last year - I think my phrasing was "Is there a difference between intention and ki" and his reply was no, they are very different things. Ki is activated by intention, and also kokyu. Though as your skill in directing ki develops, you can start to activate ki without kokyu.
Which is what I said, earlier, regarding Yi-Chi-Li (but I seem to be under the Curse of Apollo...
). Yi (Shin) drives Chi (Ki)... which drives the body and the outward expression of physical power and waza. Kokyu assists in the creation of spherical force ("peng") by providing a little boost to the change in atmospheric pressure in body cavities, until the individual is able to use other means to create the structural force by other means (manipulating internal tissues instead of depending on kokyu).